A blade connection of this general type is disclosed in U.S. Pat. No. 3,501,250. The blade mounting and the rotor hub are therein connected by a rod, into which a damping member is inserted. The damping member has the purpose of damping the lead lag mode of the rotor blades about the axis of each blade fastening pin, so that they are not transmitted onto the rotor shaft and thus onto the cabin. Further, by this means control is secured over the frequency behavior in the axis of the blade fastening pin.
A damping of the lead lag mode of the rotor blades is further secured by suitably selecting the material of the rotor blades, by controlling the friction between blade and blade mounting and by providing a rubber sleeve on the locking pin. However, the friction can spread which causes deviations in the damping.
However, the known blade connection has the disadvantage that an out-of-track condition can occur in a rotating rotor in consequence of errors of the sweepback angle caused by manufacture inaccuracies. This out-of-track condition must be balanced by trim weights in the main pin, which complicates the manufacture of the rotor and increases its weight.
Sweepback adjusting devices with push-pull struts and ball-and-socket joints between rotor blade and blade mounting or pull-in bolts are known. However, their lifetime is relatively short because of the alternating load caused by the lead lag moments.
Therefore the basic purpose of the invention is to produce a blade connection, which permits an adjustment of the sweepback angle of the rotor blades together with a good damping of the lead lag mode of the same.